Table 4. Matrix Effect Evaluation of PVLs and Creatinine in Urine by LDTD-MS/MS.

analyte	matrix	nominal concentration (μg/L)	mean concentration (μg/L)	precision (% CV)	accuracy (%)
3-HPVL (191 → 106)	#1	1250	1130.5	2.4	90.4
	#2	1250	1164.8	5.5	93.2
	#3	1250	1232.4	9.6	98.6
	#4	1250	1203.2	5.6	96.3
	#5	1250	1356.2	7.1	108.5
	#6	1250	1141.6	8.5	91.3
3,4-DHPVL (207 → 163)	#1	2500	2645.8	7.9	105.8
	#2	2500	2321.7	2.5	92.9
	#3	2500	2607.7	5.8	104.3
	#4	2500	2765.0	14.3	110.6
	#5	2500	2591.2	6.6	103.6
	#6	2500	2844.3	8.0	113.8
creatinine (114 → 86)	#1	1200	1237.3	4.6	103.1
	#2	1200	1239.5	3.6	103.3
	#3	1200	1218.7	5.7	101.6
	#4	1200	1203.7	9.6	100.3
	#5	1200	1349.7	7.0	112.5
	#6	1200	1275.2	3.2	106.3